Hello all, First post here so I appreciate any advice y'all can give. I'm considering buying a Pentax 67 to begin experimenting with medium format. I have experience with 35mm film photography but not medium format. It seems like eBay is basically the only place to buy the 67. Anyone have any other recommendations or is eBay the best bet? Also, I'm hoping to get the 105mm 2.4 lens but it seems like the glass on most have yellowed. Is this avoidable and how much of an impact on pictures does the yellowing have? Any info is greatly appreciated. Thanks!